The present invention relates to a re-sealable container including a closure which may be releasably secured in a closed position.
In the packaging industry, it is customary to distribute particulate materials such as dog food, cat food, flour, cereal, fertilizer, cement, and other dry products in a bag, box or other container. Conventional containers, particularly bags, include a front wall, a back wall and side walls, each of the walls having upper and lower ends. Normally, the lower ends of the wall members are folded to form a flap to close the lower end of the bag. The upper end of the bag is closed by folding the upper ends of the wall members downward to create a flap which is glued to the front wall member.
To pour contents from a conventional bag, a user tears a comer of the bag so that the contents may be dispensed or poured through the corner. With the corner torn, however, it is difficult to re-seal or re-close the bag.
One solution to this problem is described in U.S. Pat. No. 6,048,100 to Thrall, which discloses a bag including an upper flap permanently adhered to the front wall of the bag, except for a flap portion near one of the side walls. The flap portion includes a strip of non-stick release liner adhered to it. Strips of exposed adhesive are secured to the front wall of the bag. When the flap is folded over the exposed adhesive, the liner sticks to the adhesive and seals the bag closed along the flap portion. Because of the non-stick material, the closure is movable between a non-sealed open position and a sealed closed position.
Although the Thrall closure facilitates a bag re-sealing, it suffers shortcomings. First, the release liner and exposed adhesive frequently become contaminated with the contents of the bag as those contents are poured. Accordingly, the ability of the closure to remain closed diminishes with use. Second, because the flap portion of the closure is easily pulled from the release liner, it is difficult to detect tampering of the bag.
Another, unrelated closure system is disclosed in U.S. Pat. No. 4,824,261 to Provost. Provost discloses a pair of strips of a hook-and-loop fastening system, identified by the trademark VELCRO. One strip from the pair is hot glued across the width of the front wall of a bag. A second strip is hot glued across a closure flap, to an underside which faces the front wall. A portion of the closure flap that extends beyond the second strip is hot glued to the front wall. A piece of cording is glued to the front wall of the bag under the closure flap. The cording is used to fracture the closure flap and act as a tamper-proof closing for the bag, prior to initial opening.
The tamper-proof re-sealable system of Provost suffers shortcomings as well. First, the velcro strips extend across the width of the bag. Thus, when the strips are pulled apart along a corner, and contents are poured from that comer, the strips tend to separate across the entire width of the bag. This causes excess contents to spill from the bag. Additionally, each of the components of the closure system are individually hot-melt glued to the front wall and flap, which results in increased production costs.